Source : Webster's Revised Unabridged Dictionary (1913)

Lineman \Line"man\ (l[imac]n"m[a^]n), n.; pl. {Linemen}
   (-m[e^]n).
   1. One who carries the line in surveying, etc.

   2. A man employed to examine the rails of a railroad to see
      if they are in good condition; also, a man employed to
      repair telegraph lines.

Source : WordNet®

linemen
     n : the football players who line up on the line of scrimmage